The 21st World Cancer Congress is being held in southern China's city of Shenzhen. It's experts at the congress say one third of the disease can be prevented, and adequate measures can prevent cancer, and limit cancer deaths. Latest research show there are about 7 million cancer deaths worldwide every year, and 24 percent them are in China.

Experts say 40 percent of cancer patients are caused by lifestyle, infections and bad working conditions, and they can be prevented. They say keeping weight, a healthy diet and regular exercises can reduce one third risk of cancer. 80 percent of lung cancer is caused by smoking. But only 9 percent nations banned smoking in restaurants and bars. Changing unhealthy public lifestyle become China's important way in fight and prevent cancer.